River Thames Scheme. Jenny Marshall-Evans Environmental Scientist. Handing over design to the public did it make a difference?

Transcription

1 River Thames Scheme Handing over design to the public did it make a difference? 24 April 2018 Jenny Marshall-Evans Environmental Scientist 1 1

2 Agenda Introduction RTS Vision Deliberative approach Enhancement opportunities Design areas influenced Engagement shaped the Vision 2 2

3 14.6 km long m wide 150 m 3 /s 2-3m deep Schematic 3 Intro The River Thames Scheme (Datchetto Teddington) is one of the UKs largest flood risk management schemes of recent years. It involves construction of a 15km long flood relief channel through west London. Black & Veatch is leading outline design for the Environment Agency and partners. The new flood channel is in 3 sections (red dashed lines). Nearly 15km in length and Up to 50m wide Flow capacity of 150m3/s 2-3 m deep, but water level increases by c.1mwhen channel in operation 3

4 New opportunities for tourism/recreation/sport Improving access to the river Improving landscape and habitats 4 The vision consists of 3 elements: - Protecting the communities in the area by reducing flood risk - Securing the economy by keeping businesses and transport running, allowing the communities to thrive and encouraging investment It is the last item where our vision goes beyond the functional and becomes more aspirational. - To enhance the area by providing new opportunities for tourism, recreation and sport; improving access to the River Thames; and improving the landscape and surrounding habitats. In response to this vision, the project team has placed strong focus on the landscape and environmental design. Of course, the design has to function as a flood scheme, but to deliver these wider benefits the scheme needed to be ambitious in its aspirations, and ensure landscape and environment were at the centre and fully integrated into the design. It was with these aspirations in mind that we sought to engage the public in the design. 4

5 Deliberative engagement 5 A deliberative approach was adopted to engage with the wide variety of stakeholders, including authorities, user groups, conservation bodies and landowner The Discussion Groups help stakeholders to work through the complexities of the channel design. The key objectives are to give participants an opportunity to: share their views, knowledge and expertise, suggest ideas; and explore options about what the channel could look like and how it can be used; whilst also ensuring that it creates benefits for people, livelihoods and nature. By using this approach, we hoped to maximise the potential for the Project to deliver mutually acceptable designs that bring multifunctional benefits, attract partnership and investment funding, and empower community groups, organisations and businesses to be stewards of the improvements it will deliver. Incorporated stakeholders in the iterative design process, including consideration of the potential environmental effects. -Minimising the projects environmental impact and enhancing the benefits, as part of the EIA process. 5

6 Channel section 1 Green:natural ground Pink: landfill Blue:flood embankments 6 We identified an area where we felt there was a better route to that agreed in the original Strategy, and wanted the discussion group to be a part of the option appraisal process. On this drawing, there is a long section of channel through landfill (as shown in the pink), and our ground investigations showed this to be a particularly nasty site, with medical waste found. We therefore considered some alternatives. 6

7 Influencing the design 6 options 7 Using: Optional appraisal using multi-criteria evaluation Feedback from Discussion Groups Consensus building at final Discussion Group Workshops Concerns - potential effect the introduction of River Thames water would have on the lakes water quality, - the risk of introducing invasive species and - the affects the different options would have on recreation in the lake (especially as the northern lake is currently a commercial fishery and the southern is used by a sailing club). 7

8 100% 80% 60% Strongly support Support Neutral 40% Opposed 20% 0% Strategy (n = 22) 1 (n = 27) 2 (n = 25) 3 (n = 24) 4 (n = 26) 5 (n = 26) Options Actively object Option 1 selected 8 There was strong opposition to the Strategy option through the landfill and also for options 2 and 3 which had the greatest impact on recreation in the lake. The most favoured options (or the least opposed) were options 1 and 4. We later undertook groundwater and water quality modelling to assess the impact on water quality, and using this were able to demonstrate to Natural England (needed because the lake is part of the South West London Water Bodies Special Protection Area) that it was not necessary to isolate the flood water from the River Thames from the rest of the lakes, so separation embankments were not required. A consensus was reached. 8

9 Building consensus Green:natural ground Pink: landfill Blue:flood embankments Second example: This shows the original strategy alignment -a straight, trapezoidal channel, through natural ground. Flood embankment to the north to protect the Chertsey water treatment works. 9

10 Building consensus 10 The first workshop asked for ideas for enhancements from stakeholders, including areas of habitat creation, footpaths, viewpoints etc Using the stakeholder idea for habitat creation in this area we subsequently developed our habitats strategy and led us to focus our efforts on specific locations, such as the channel at Abbey Meads. 10

11 Abbey Meads 100% 80% 60% 40% 20% Strongly support Support Neutral Opposed Actively object 0% Abbey Meads 11 In consultationwith Affinity Water identified the need for a shallow, wider channel in this area to prevent affecting their groundwater abstraction requirements. Havingdeveloped a habitats concept using the views from the first workshop the proposed concept was presented to stakeholders at the second workshop. No one actively objected to design and overall the majority supported it We were able to build consensus on this section of the channel. 11

12 Abbey Meads 12 Using the ideas provided from the discussion groups, expertise from the Project Team and engagement with the water utility company we were able to develop a concept for this area of the channel that met the needs and aspirations of all stakeholders and contributed to achieving all elements of the RTS vision. We have further developed the design, due to the consensus built from the discussion groups and have created an area of high value habitat enhancements, incorporating the entire area in to the channel to create a wet meadow that will be partially flooded in winter and largely dry in summer with rough grazing during the summer months. 12

13 Shaping the Vision 13 Third example: On this drawing there is an existing landfill site it s been poorly restored - and has a degraded landscape. The project, by its nature of excavating a flood channel, generates an excess of freely available material (approximately 1.5 million cubic meters). An initial concept for a raised landform was sketched then a more detailed drawing of 2 options presented to the discussion groups: - option 1 was the development of country park - Option 2 was a sports and activities recreation center 13

14 Manor Farm 100% Percentage of votes received 80% 60% 40% 20% 0% Manor Farm Option 1 Manor Farm Option 2 Options Strongly support Support Neutral Option 1 selected 14 The Discussion Group Workshop preferred the concept proposals for option 1. Stakeholders had several concerns with option 2, with 47% expressing concerns and only 6% expressing support for the Active Leisure & Development concept. Option 1 was subsequently taken forwards as the chosen configuration for the LEA. In certain instances, specific comments from the Discussion Group Workshop were carried over into the LEA design such as Planting of trees along M3 motorway to improve air quality. 14

15 Manor Farm Artist s Impression Great, exactly the type of landscape opportunity we would like out of the scheme 15 Not only did feedback from the Discussion Groups factor into the decisions for the locations of the LEAs, but attendees also had the opportunity to comment on specific aspects of the concept plans. Across the sites, there was general support expressed for the beacons concept, additional access routes and the general landscape enhancements, all of which have been included in the outline design. 15

16 Beacon concept 16 Beacon concept: Provide visual connectivity between the different channel sections with views between 4 Beacons along the flood channel, but also to other landmarks in the area 16

17 106 ha country parks 183 ha habitat 23 km footpaths/ cycle ways Human/natural benefits 4 km navigable channel 17 - The scheme will deliver a 106 ha of new publicly accessible country parks, with car parking and visitor facilities (this is equates to roughly three quarters the size of Hyde Park) - It will create 183 ha of habitat, with this figure increasing to 250 ha on completion km of new footpaths and cycle ways linking into the existing networks; and - 4km of new navigable channel 17

18 Summary Deliberative approach: Two-way dialogue Local knowledge and expertise Collaborative design 18 Through a series of meetings, stakeholders suggested 100 s of enhancement opportunities that were captured in the design of the channel and surrounding landscape. It will summarise how: a) design suggestions from stakeholders were incorporated and shaped a vision that linked the history of the River Thames with the functionality of the scheme; b) consultees were able to influence areas of uncertainty. Specific examples will be shown of design areas that were influenced by engagement. 18

19 Jenny Marshall-Evans Black & Veatch Ltd., 60 High Street, Redhill, RH1 1SH th April